Analysis of fluorocarbon plasma-treated diamond powders by solid-state fluorine-19 Nuclear Magnetic Resonance

Journal Article · Thu Sep 09 04:00:00 EDT 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100138a020· OSTI ID:5526265

Scruggs, B E; Gleason, K K ^[1]

---

1. Massachusetts Inst. of Technology, Cambridge (United States)

In this work, solid-state [sup 19]F NMR has been used to characterize fluorine on diamond powder surfaces after CF[sub 4] and 98% CF[sub 4]2% O[sub 2] radio-frequency plasma treatment. The fluorine surface coverage of the pure CF[sub 4] treated powder was 7.1 [times] 10[sup 14] F/cm[sup 2] while the other plasma yielded a much lower coverage, 7.4 [times] 10[sup 13] F/cm[sup 2]. In both cases, only CF[sub x] (x = 1-3) functionalities were observed with the majority species being carbon monofluoride. Only 5-10% of the fluorine was bonded as CF[sub 3]. With high-speed magic-angle spinning, isotropic chemical shifts were resolved and assigned relative to CFCl[sub 3] as follows: CF, 148 [+-] 1 ppm; CF[sub 2], 106 [+-] 2 and 123 ppm; CF[sub 3], 78 [+-] 1 ppm. The peak at 123 ppm was only observed in the CF[sub 4]O[sub 2] plasma-treated sample and is speculated to be the result of atomic fluorine etching of diamond. Multiple-quantum NMR indicates that fluorine coverage is not uniform. Some fluorine is relatively dispersed on the order of approximately 5 Angstroms while the remaining fluorine occurs in aggregates of greater than 40 nuclei. This is consistent with preferential deposition of reaction occurring at and around surface defects. 51 refs., 10 figs., 5 tabs.

• OSTI ID: 5526265
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 97:36; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360600 -- Other Materials
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON
CARBON TETRAFLUORIDE
CHEMICAL COATING
CHEMICAL REACTIONS
CHEMICAL SHIFT
CHEMICAL VAPOR DEPOSITION
DEPOSITION
DIAMONDS
ELEMENTAL MINERALS
ELEMENTS
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINATION
FLUORINE 19
FLUORINE ISOTOPES
HALOGENATED ALIPHATIC HYDROCARBONS
HALOGENATION
ISOTOPES
LIGHT NUCLEI
MINERALS
NMR SPECTRA
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PLASMA
POWDERS
SPECTRA
STABLE ISOTOPES
SURFACE COATING
SURFACE TREATMENTS